诺氟沙星对MABR处理生活污水的影响

Effect of Norfloxacin on MABR Treatment of Domestic Sewage

近年来,各类污废水中多会检测出诺氟沙星(NOR)。为了研究NOR对膜曝气生物反应器(MABR)处理生活污水的作用机制,考察了不同NOR浓度对污染物去除效果、悬浮污泥特性以及系统内微生物菌群变化的影响。结果表明:在NOR浓度为20~500μg/L范围内,随NOR浓度的增加,MABR对COD和NOR的去除率没有明显降低,可达80%左右;NOR浓度对去除NH_(4)^(+)-N和TN影响较大,NH_(4)^(+)-N去除率从96.4%降低至35.6%,TN去除率从72.4%降低至30.6%。NOR使悬浮污泥中的功能微生物AOB和NOB活性下降,DNB活性呈先上升后下降的趋势;微生物为抵抗NOR而分泌大量的EPS,增加了蛋白质和多糖的含量。对比Alpha多样性可知,NOR浓度对菌群丰度和多样性影响较大,MABR生物膜和悬浮污泥菌群组成存在差异,生物膜内的微生物比悬浮污泥对NOR的抗冲击性强,说明MABR系统内特殊的生物相构成对处理含高浓度NOR的生活污水具有可行性。

In recent years,norfloxacin(NOR)has been detected in many types of wastewater.In order to study NOR the membrane aeration bioreactor(MABR)deal with the mechanism of action of sewage,examines the different NOR concentration,suspended sludge depurative effect for contamination removal characteristics and the influence of microbial flora in the system change.The results show that in the range of NOR concentration 20~500μg/L,the removal rate of COD and NOR by MABR does not decrease significantly with the increase of NOR concentration,and can reach about 80%.NOR concentration has a great influence on the removal of NH_(4)^(+)-N and TN.The removal rate ofNH_(4)^(+)-N decreases from 96.4%to 35.6%,and the TN removal rate decreases from 72.4%to 30.6%.The activity of AOB and NOB in suspended sludge was decreased by NOR,and the activity of DNB was increased first and then decreased.Microorganisms secrete a large amount of EPS to resist NOR,which increases the content of protein and polysaccharide.Compared with Alpha diversity,it can be seen that the concentration of NOR has a great influence on the abundance and diversity of bacteria,and the composition of bacteria in MABR biofilm and suspended sludge is different.Microorganisms in biofilm have stronger impact resistance to NOR than suspended sludge,indicating that the special biophase composition in MABR system is feasible for treating domestic sewage containing high concentration of NOR.